1. Field of the Invention
The present invention relates to a data storage media, and more particularly to a data storage media comprising at least a cyanine-TCNQ complex dye, which cyanine-TCNQ complex dye has a maximum absorption and high fluorescent quantum efficiency in the light region of wavelength ranging between xcex=400 nmxcx9c800 nm.
2. Description of the Prior Art
A data storage medium with higher storage density, smaller size and lower cost is highly demanded. As magnetic storage medium is unable to satisfy these requirements, optical storage material is greatly sought for as an alternative. Ever since the discovery of the inherent photosensitizing property of organic dyes making it suitable for making optical data recording media, organic dyes have become useful and interesting research and development subject in electronics industry. Presently, organic dyes are widely used for making recording media for data storage because of their inherent photosensitizing property. The applications of organic dye include in the fields of, for example, nonlinear optical device, recording and displaying of optical disc data, photoresist, sensor and indicator for heat, light, and electron, during the transfer and storage of energy, medicine and biology, etc.
Cyanine blue having cyanine structure was first synthesized by Greville Williams in 1856 (K. Venkataraman (ed.), The Chemistry of Synthetic Dyes, Vol.II, pp.1143-1186, Academic Press, New York, 1952). In 1875, Vogel discovered that cyanine blue has specific photosensitizing properties. Therefore, cyanine blue, which was originally used as dye for textile, is also widely used in electronics industry for producing value-added data storage media. Cyanine dye exhibits excellent photosensitizing property in UV/Visible to IR. Accordingly, cyanine dye can also used as a photoresist layer in semiconductor processing and as optical data storage medium in electronic industry.
Cyanine TCNQ complex was first synthesized by J. H. Lupinski et al. in 1967. (xe2x80x9cTetracyanoquinodimethane Derivatives of Cyanine Dyesxe2x80x9d, Vol. 3, pp.241-250, Molecular Crystals, Great Britain, 1967.) In 1981, 3,3xe2x80x2-diethyl-12-acetyl-thiatetracyanine perchlorate was first proposed for application in optical disc fabrication by Law et al. (K. Y. Law, P. S. Vincett, and G. E. Johnson, Appl. Phys. Lett., 39, 718 (1981)). The cyanine dye and PVAc (poly(vinyl acetate)) were first mixed and then spin-coated to form an optical recording medium. After this successful application, a variety of cyanine dyes were developed for optical disc applications, such as those disclosed in U.S. Pat. Nos. 5,019,476, 5,292,615, 5,328,802, 5,332,608, 5,424,171, 5,455,094, and 5,579,150 etc.
However, organic compounds containing the polymethine structure have a poor photostability. General cyanine dye also has the same problem since it belongs to this group of compound. Hence, it is desirable to develop a new cyanine dye having an excellent photostability. In 1999, Shin-ichi Morishima et al., Fuji-film company in Japan, attempted to use the doping method. (Shin-ichi Morishima et al., Jpn. J. Appl. Phys. Vol. 38 (1999), pp.1634-1637). Addition of neutral TCNQ derivative to dye increases the photostability of dye, however, TCNQ is not quite soluble in the common organic solvents so that content of doping dye formulation is limited, therefore, the stability effect is also limited.
Accordingly, it is an object of this invention to resolve the drawbacks as described above.
It is another object of this invention to provide a data storage media comprising at least a cyanine-TCNQ complex dye, which cyanine-TCNQ complex dye has a high oxidation potential for preventing the oxidation of dyes.
It is another object of this invention to provide a data storage media comprising at least a cyanine-TCNQ complex dye, which cyanine-TCNQ complex dye has a maximum absorption in light region having wavelength in the range of 400xcx9c800 nm and possess high fluorescent quantum efficiency.
It is another object of the present invention to provide a data storage media comprising at least a cyanine-TCNQ complex dye, which cyanine-TCNQ complex dye has a better solubility in a variety of organic solvents so that a stable homogenous solution with uniform distribution of cyanine-TCNQ complex dye can be obtained. Thus a high quality coating using this solution can be achieved for making a high quality data storage media for recording purpose.
It is another object of this invention to provide a data storage media comprising at least a cyanine-TCNQ complex dye, which cyanine-TCNQ complex dye has a photostabilizing feature. Thus cost of a photostabilizing agent can be effectively avoided, and therefore the manufacturing cost can be effectively reduced.
In accordance with the above objects and other advantages as broadly described herein, the present invention provides a data storage media comprising at least a cyanine-TCNQ complex dye having a structural formula (I) as shown in the following: 
wherein Q and Qxe2x80x2 denote aromatic or polyaromatic, R1 and R2 denote one of alkyl, arylester, alkoxy, alkylthio, and alkoxythio etc., n represents an integer of 0, 1, 2, and 3. The TCNQ-m represents 7,7xe2x80x2,8,8xe2x80x2-tetracyanoquinodimethane and its derivatives, and wherein m is an integer of 1 or 2. The cyanine-TCNQ complex dye has a maximum absorption and high fluorescent quantum efficiency in the light region having wavelength in the range of xcex=400 nmxcx9c800 nm. The data storage media comprising the cyanine-TCNQ complex dye of the present invention can be, but not limited, to a reflection optical recording media or a non-reflection fluorescent optical recording media suiting the requirement.